Free Convection Heat Transfer of Alumina-Water Nanofluid in an Enclosure: Assessment of Viscosity and Conductivity Models

In this paper, the free convection heat transfer of Al2O3-Water nanofluid in a square cavity is simulated, employing the finite volume technique. The homogeneous model is utilized to determine the influence of nanoparticles. The obtained results are compared with the experiment. At higher Rayleigh numbers, higher agreement between the results is observed. The nanofluid average Nusselt number increases with the Rayleigh number. For a concentration of 0.1%, the average Nusselt number increases, and for higher concentrations, it decreases, as compared with the pure fluid. Different viscosity and conductivity models were evaluated. It was found that the viscosity correlation, which takes into account the Brownian motion effect, produces more accurate results. The results obtained using different conductivity correlations were almost the same